End-stage renal disease (ESRD) is characterized by a complete or near complete failure of the kidneys to function to excrete wastes, concentrate urine, and regulate electrolytes. In such cases, kidney function is so low that complications are multiple and severe, and death will occur from accumulation of fluids and waste products in the body.
A common life-sustaining treatment for patients with ESRD is hemodialysis. Hemodialysis is a process whereby large amounts of blood are rapidly removed from the body and filtered through a machine that removes wastes and extra fluid. The cleaned blood is then returned back into the body.
An important step before starting regular hemodialysis is preparing a vascular access, which is a site on the body where blood will be removed and returned during dialysis. In this regard, creation of an arteriovenous fistula (AV fistula) is a commonly performed operation in which an artery is connected directly to a vein. The high blood pressure of the artery causes more blood to flow into the vein and, as a result, the vein dilates growing larger and stronger.
However, to connect the patient to a dialysis machine, a nurse or some other medical technician must insert a large gauge needle through the skin into the AV fistula. The technique of cannulating an AV fistula for dialysis requires considerable skill. The AV fistula often lies several centimeters below the surface of the skin and cannot be located by visual inspection. A medical technician is forced to locate the AV fistula by palpation. Since resistance to blood flow in the vein is low, a pulse is usually not present in the AV fistula. The tactile clue utilized to locate the AV fistula is a vibration caused by turbulent blood flow in the vein. The medical technician tries to identify the location of maximum vibration on the surface of the skin with his/her fingertip to identify the location of the underlying AV fistula in order to cannulate it. If the medical technician is unable to properly identify the correct location of the AV fistula, the dialysis needle may inadvertently puncture the side rather than the center of the AV fistula and result in damage and significant bleeding or thrombosis of the AV fistula. Thus, a need exists for a device and method that can simplify the technique of AV fistula cannulation.